Blanking switch associated with variable wave guide antenna



July 20, 1954 5, gram 2,684,410

BLANKING SWITCH ASSOCIATED WITH VARIABLE WAVE GUIDE ANTENNA Filed Feb.21, 1951 2 Sheets-Sheet l INVENTOR. aw?

prraewsys' lllwT July 20, 1954 R. E. STEIN 2,684,410

Filed Feb. 21, 1951 2 Sheets-Sheet 2 i Fig.5.

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Patented July 20, 1954 BLANKING SWITCH ASSOCIATED WITH VARIABLE ill/AVEGUIDE ANTENNA Romar E. Stein, Los Angeles, Calif., assignor to GilfillanBros., Inc., Los Angeles, Calif., a corporation of CaliforniaApplication February 21, 1951, Serial No. 212,098

6 Claims.

The present invention relates to an improved switch constructioncharacterized by its adjustment features, and is particularly useful forcontrolling an electrical circuit associated with the movable wave guideelement of a radar antenna for energizing related circuits inpredetermined time relationship with respect to the scanning movement ofthe radiated antenna beam.

in radar installations, a variable wave guide antenna is used forpurposes of radiating an antenna beam in a predetermined direction, thedirection being cyclically varied, to obtain a scanningor sweeping ofsuch antenna beam in space by oscillating a wave guide element. Otherparts of the radar installation require related cir cuits to beenergized in accordance with the particular angular position of theradiating beam, and for that purpose, as shown herein, a switch iscoupled to the oscillatory wave guide element so as to be operated insynchronism, at predetermined times, in relationship to the scanningmovement of the antenna beam.

The present invention therefore contemplates the provision of animproved switch operating in synchronism with such oscillatory waveguide member, the switch being constructed so as to give long life andbeing capable of precise adjustment whereby the switch may be adjustedto compensate for mechanical variations in different antennas with whichit is used.

An object of the present invention, therefore, is to provide an improvedswitch construction for accomplishing the aforementioned purposes.

A specific object of the present invention is to provide an improvedswitch of this character which is closed for a selected period of timewhile the associated wave guide member moves between its extreme limitsof oscillatory movement.

Another specific object of the present invention is to provide animproved switch of the type mentioned in the previous paragraph whichincorporates adjustment means whereby the switch may be adjusted to openat any point with re spect to either end of travel of the oscillatorywave guide member.

Another specific object of the present invention is to provide animproved switch of this character which may be adjusted to open atpredetermined points with respect to either end of movement of theoscillatory wave guide member, and further incorporates adjustment meanswhereby the period during which the switch is closed may be adjustedwith respect to any selected portion of travel of the oscillatorymember.

guide Another specific object of the present invention is to provide animproved switch of this character which is of rugged construction andcapable of being operated over a long period of time without failure.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. This inventionitself, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may be best understood byreference to the following description taken in connection with theaccompanying drawings in which:

Figure 1 is a view in end elevation of a switch associated with avariable wave guide radar antenna in accordance with features of thepresent invention, certain parts of the structure shown being brokenaway and fragmented for purposes of more clearly illustrating internalstructure;

Figure 2 is a View in plan of the switch shown in Figure l, but withcertain parts thereof fragmented and sectioned for purposes of showinginternal structure;

Figure 3 is a view taken generally as indicated by the line 3-3 inFigure l; and

Figure 4 is a sectional view taken on the line 4-4 of Figure 3.

Referring to Figure 1, the switch casing housing or base I0 is firmlymounted as, for example, by releasable bolts l i to the stationary waveguide element l2 of the radar antenna l3. The other wave guide elementM, which cooperates with the stationary guide element l2, is oscillatedvertically in Figure l, as indicated by the arrows l5, by conventionalmeans which are not shown here. The effect of such oscillatory movementrepresented by the arrows i5 is to cyclically vary the spacing, i. e.,the so-called A-dimension, defined by the operation of the legs lZA, MAon the stationary and movable guide members, respectively. By thuscyclically varying the spacing, i. e., the so-called A-dimension, ascanning movement is imparted to the highly directional antenna beamradiated by a series of dipoles it, each of which are mounted 011 theguide member [2 with a probe thereof extending into the variable widthwave guide defined by the legs (2A, MA. The stationary guide member l2may have mounted thereon a longitudinally extending parasitic reflectorIT.

The switch in the casing 10 is operated in timed relationship withmovement of the variable wave guide member 14, and the time during whichit is operated, as described in detail hereinafter,

may be adjusted with respect to either end of travel of the guide memberI4, and further may be adjusted to remain closed during any selectedperiod corresponding to a selected period of travel of the guide memberi i. For purposes of actuating the switch, which has the generalreference numeral is (such switch iii, in fact, comprising eightswitches as described hereinafter), a pair of upwardly extending arms 29(Figures 1 and 3) is interconnected between the movable guide member illand the movable portion 22 of the switch is. The lower ends of thesearms are releasably fastened to the guide member it by machine bolts 23.

Actually, the switch l9 includes four identically constructed switches24, 24, 24, 24 in the upper deck (Figure 1) and four identicallyconstructed switches 25, 25, 25, 25 in the lower deck. Correspondingones of such switches, 24, 25, as shown in Figure 1, are seriallyconnected to an upper deck terminal 26 and a lower deck terminal 2?.

Briefly, the upper deck switch :24 .is actuated in upward movement ofthe guide member l4, and the lower deck switch 25 is actuated indownward movement of the guide member [4, and the point at which theswitches 24, 25 are operated, i. e., opened, with respect to the upperand lower limits of travel of the guide member I4,

may be adjusted by corresponding upper and lower deck adjustment screws28 and 29. Since there are four upper deck switches 24, there are fourcorresponding adjustment screws 28., and likewise there is an adjustmentscrew 29 for each of the four lower deck switches 25. Further, byadjusting the angular position of the upper cam 30, each of the upperdeck switches 2 may be adjusted in unison; likewise, by adjusting theangular position of the lower cam ti, each of the lower deck switches 25may be adjusted in unison.

It is observed, with reference to Figure 1, that each of the switches ii, 25 have a common element, namely, the generally V-shaped springelement 32 which is affixed to the housing Hi by bolt 33 with contactelements mounted on each of its free ends, such contact elementscooperating with like contact elements mounted on the insulated leafsprings 3t, 35. These leaf springs 34, 35 are mounted on the post 3'? ofinsulating material, which is bolted to the casing I8 with projectingends of such leaf springs 34, 35 providing terminals 26, it is observedthat the V-shaped switch spring element 32 is insulated from the casingiii.

It is observed, as clearly shown in Figure 4, that the free ends of theV-shaped spring switch element 32 cooperates with the rounded reducedends of the adjustment screws 23, 29, in such a manner thatcorresponding free ends may be adjusted physically with reference to thecorresponding spring elements 34, 35 whereby the point at which theswitches 24, 25 are operated, i. e., opened, with respect to upper andlower movement of the arm 28, may be adjusted. Various means may be usedto lock the adjustment screws 28, 2% in their adjusted position, andsuch means, since they are preferred, are shown herein as looking platesas, all which cooperate with the shanks of the screws 28, 2Q,respectively, to secure the same against movement.

The switches 2:8, 25 actually are both normally closed switches, asshown in Figure 4, and switch 2 2 is caused to be opened upon engagementof the switch 25 is opened upon engagement of the cam 3i with the springelement 35. Both of these cam members 30, 3| have their opposite endssupported on the upper ends of the arms 28, 2s, one end of these cams38, 3! being slip fitted into one of the arms 20, whereas the other endof these cams 39, 3! is locked to the other arm 20, as shown :in Figurel, by a clamping plate ii, the opposite ends of which are bolted to thearm 2E so as to clamp each of the cams 3e, 3! between the plate GI andthe upper end of such arm 20.

Each of these cams 30, 3! may comprise simply an insulating rod with asmaller rod passing through an eccentrically located bore in the largerrod, and with both the larger and smaller rods afiixed together, as forexample, by a pin or set screw. Such smaller rod has one of its endsprovided with a hexagon head and screw driver adjustment slot, so thatthe assembly comprising such larger and smaller rods may be rotated todifferent adjusted positions once the clamping plate All is released.

It is evident that adjustment or the cam 30 efifects the time at whicheach of the upper deck switches 24 is operated; similarly, adjustment ofthe lower cam 31 effects the time at which each of the lower deckswitches 25 is operated.

ifferent electrical circuits connected to terminals 2t, 2? are thusnormally closed in intermediate position of the oscillatory wave guidemember 24 which, as mentioned previously, oscillates in the directionindicated by the arrows It in Figure 1. It is only when the guide memberi4 is moved towards either one of its extreme positions that eitherswitch 2 or 25, as the case may be, is interrupted to thereby interruptsuch electrical control circuit which includes, for purposes ofreference, the terminal 2%, switch element 24, switch element 25 andterminal It is obvious from the foregoing description that the point atwhich the switch 2%, 25 is operated with reference to the angularposition of the antenna beam radiated from the antenna 13 may beadjusted individually by corresponding adjustment screws 28, 29 whichare thus capable of providing a compensatory effect for unpredictableoperation of the antenna.

.After once installing the composite switch It on the wave guide antenna13, the individual switches 24, 25 are adjusted by adjustment of thecorresponding adjustment screws 25, 2s. Later, when it is desired toinstall the same switch on a difierent antenna of the same noveldimensions, or to re-install the same switch on an antenna after it hasbeen repaired, or, more important, upon replacement of a magnetron,adjustment of each of the switches E lor 25 in unison may be effected byadjustment of the corresponding cam 35, 3|, thereby avoiding thenecessity of adjusting each of the screws 28, 29, individually.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the art thatchanges and modifications maybe made without departing from thisinvention in its broader aspects and, therefore, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scope of this invention.

I claim:

1. Ina switch of the character described, a housing, :a generallyV-shaped spring element having an intermediate portion thereof affixedto said housing, a pair of cantilever supported spring elements eachcooperating with opposite free ends of said V-shaped spring element, apair of adjustment screws mounted on said housing and adapted to engageand move corresponding opposite legs of said Vshaped spring element todifferent adjusted positions, a movable switch actuating elementincluding a pair of generally parallel extending adjustable camsarranged to engage and. move opposite ones of said pair of cantileversupported spring elements.

2. In a switch of the character described, a switch base, a generallyV-shaped spring switch element attached at a point intermediate its endsto said base, means mounted on said base for adjusting independently theposition of opposite free ends of said V-shaped element, a pair ofcantilever supported spring elements having opposite free ends thereofcooperating with opposite free ends of said V-shaped element to form apair of switches, a movable switch actuating member mounted for movementrelative to said base and comprising a pair of adjustably positionedcams engageable with opposite ones of said cantilever supported springelements.

3. In a switch of the character described, a base, a first pair ofresilient cantilever supported switch arms on said base, adjustablemeans on said base for adjusting the position of the free ends of eachor" said arms, a second pair of resilient cantilever supported switcharms cooperating respectively with opposite ones of the first pair ofswitch arms to provide a pair of switches which remain normally closedin the adjustable range of said adjustable means, switch actuating meansmovably mounted .with respect to said base, said switch actuating meansincluding a pair of adjustably positioned elements adapted to engage andto move corresponding ones of said second pair of cantilever supportedswitch arms.

a. In an arrangement of the character described, a movable elementreciprocablein a first direction and a stationary element, a switch baseaiiixed stationarily with respect to said stationary element, a firstpair of cantilever supported switch arms mounted on said base, a pair ofadjustment screws having their longitudinal axes extending generallyperpendicular to said first direction and engaging opposite ones of saidair of switch elements to adjust their respective positions, a secondpair of cantilever supported switch eiements cooperating withcorresponding ones of said first pair of switch elements to provide apair of serially connected switches, a switch actuating member aifixedto said movable element, said switch actuating member comprising a pairof adjustably positioned cams each functioning to engage and to movecorresponding ones of said second pair of switch elements.

5. In a switch of the character described, a base, a first pair ofresilient cantilever supported switch elements mounted on said base, apair of adjusting elements on said base cooperating with a correspondingone of said pair of resilient switch elements to adjust their respectivepositions, a second pair of cantilever supported switch elements on saidbase and engageable with said first pair of switch elements in theadjustment range of said adjusting elements, a reciprocable switchactuating member, means mounting said reciprocable switch actuatingmember for reciprocal movement with respect to said base, said switchactuating member including a pair of adjustably positioned elementsfunctioning to engage and move a corresponding one of said second pairof cantilever supported switch elements.

6. In an arrangement of the character described, a switch base, a seriesof generally V- shaped spring switch elements each being aligned andhaving an intermediate portion thereof af fixed to said base, each ofsaid generally V- shaped switch elements having associated therewith apair of adjustment screws, adjustably positioned on said base andfunctioning to engage and to move opposite free ends of a correspondingone of said V-shaped spring elements to different adjusted positions, aseries of pairs of cantilever supported switch elements each havingopposite free ends thereof cooperating with opposite free ends of saidV-shaped spring elements, a reciprocable switch actuating member, saidswitch actuating member carrying a pair of cam members which extendparallel to each other and parallel to the aligned axes of the first andsecand mentioned series of switch elements, said cam members functioningto engage and to move in unison opposite ones of said second series ofswitch elements.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,671,615 Spahr May 29, 1928 1,89 i,025 Dennison et al Jan.10, 1933 2,079,252 I-Iealy May 4, 1937 2,415,242 I-Iershberger Feb. 4,1947 2,520,270 Batcheller Aug. 29, 1950

